The present invention relates to measuring devices and more particularly to measuring devices for determining the average distance between the ball retainer seating rings of a ball valve.
Heretofore inside calipers have been utilized to measure the distance between the ball retainer seating rings of a ball valve. The measurement is accomplished by removing the valve bonnet, ball, ball retainers and other operating mechanisms within the valve body. The calipers are then inserted into the valve body and adjusted until the probes or tips of the calipers touch the opposing faces of the two ball retainer seating rings. Because the opposing faces of the seating rings are not in parallel planes, the measurement is inaccurate if the probes do not contact the surfaces at points such that an imaginary line extending through the points of contact is parallel to the axis of the inlet and outlet bores of the valve. This means that the points of contact must be precisely the same in both the X and Y directions relative to the axis thus making the measurement difficult.